Internal-combustion engine



Patented Dec. 9, 1924,

RICHARD KRUTINA, OF Z'UG, SWITZERLAND.

INTERNAL-COMBUSTION ENGINE.

Application filed June 3,

To all whom it may concern:

Be it known that I, Biol-men KRUTINA, a citizen of the Republic of Germany, residing at Zug, Switzerland, have invented certain new and useful Improvements in internal- Combustion Engines, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to improvements in internal combustion engines and has particularly reference to the braking by means of such engines.

It is already known with four stroke cycle internal combustion engines to obtain a braking action by using a cycle of the controlling gear during the braking that is different from that used during the normal power generating operation. This can be effected by providing additional cams on the cam shaft and means for shifting the cam shaft endwise into the braking position, or means may be provided to cause an angular displacement of the cam shaft relatively to the engine crank shaft or both above mentioned means may be combined. However, these provisions render such an engine much more complicated than engines having an unchangeable cycle of the controlling gear.

According to the present invention the braking action is obtained, Whilst maintain" ing the controlling cycle of the cylinder inlet and outlet organs unchanged as for the ordinary run of the engine, by providing an auxiliary device influenced by the cycle but independent of the cam shaft this device is switched in when a braking action by means of the internal combustion engine is required and is cut out again when the engine is put to normal work and which causes the engine to work as a compressor absorbing power whereby the braking action results. i

The auxiliary device is attached to every engine cylinder and comprises a shut-oft organ and a valve having a displaceable piston controlling discharge ports and an air buffer, and the operation of the device is such that when the shut-elf organ is operated the movement of the piston is controlled by the compression and suction action of the internal combustion engine and by the air buffer.

The discharge ports of the auxiliary device on each engine cylinder may preferably be connected by piping to the exhaust pipe of the engine and a shut-ofi' organ is inserted in the exhaust pipe, whereby the latter 1924. Serial No. 717,545.

may be closed against the open atmosphere when the engine acts as brake in order to obtain an additional braking effect.

An embodiment of the device according to the invention is illustrated by way of example in the arompanying drawings, in

a which:

Fig. 1 is a diagrammatical vertical section through the top port of a cylinder of a four stroke cycle internal combustion engine provided with the auxiliary device.

Fig. 2 shows on an enlarged scale a vertical section through the device.

Fig. 3 shows a detail modification.

Fig. 4 shows a further embodiment of the invention and Fig. 5 is a modification of the auxiliary device in a vertical section, the shut-off organ being omitted.

Referring now to Fig. 1 of the drawing, 1 denotes the engine cylinder and 2 is the piston, 3 is the inlet valve and 4 is the outlet valve, and 5 designates the sparking plug. The other parts of the internal combustion engine such as a crank-shaft, piston rod, controlling gear and so on are of the known type and are therefore not shown in the drawings. The auxiliary device causing the braking action is shown on a larger scale in Fig. 2.

The auxiliary device comp-rises two main parts, i. e., the shut-off organ and the brake valve. The shutoff organ may be designed as a stop-cock and consists of the casing 7 and the plug 8. The lower end of the easing is provided with a screw thread nipple 15 so that the device can be screwed into the cylinder head just like a sparking plug,

The brake valve consists of the casing 9 the lower end of which is screwed into the casing 7 of the. stop cock. 10 and 11 denote discharge ports provided in the casing 9, the upper end of which is closed by the screwed-in lid 12 provided with a comparatively small bore 13 by means of which the interior of the casing is in communication with the surrounding atmosphere. A piston 14 fits loosely in the bore of the easing 9 and is displaceable therein.

"When the internal combustion engine is driven for instance by another prime mover or, with engines for vehicles, by the vehicle running down an incline, the engine absorbs power to overcome the frictional resistance in the cylinders, the controlling gear and the crank gear and to cause the compresof the auxiliary device serves now to utilize the compression work in the following manner:

When the cock 7, 8 is opened. and the supply of fuel is stopped the pressure, which increases as the piston of the englne moves upwardly during the compression stroke. acts upon the lower face of the valve piston 14 and tends to lift the latter. When the valve piston raises the pressure of the air above the piston increases and the portion of the valve above the valve piston acts as an air bufi'er or an air cushion. If the lid 12 were fluid tight the pressure above the piston 14 would be equal to the pressure oi the compression in the cylinder when the valve piston takes up the position indicated in chain dotted lines in Which position the discharge ports 10 and 11 are not uncovered. The bore 13 and thereby the ratio of compression in the valve cylinder are so chosen that the lower part of the piston 1.4 uncovers the discl'iarge ports 10 and 11 shortly before the maximum compression pressure in the engine cylinder is reached.

Now, the air compressed in the engine cylinder escapes. As the air above the piston 14 is expelled through the bore 13 and as no counterpressure is present above the piston 14, the ports 10 and 11 remain uncovered until after the air pressure in the,

engine cylinder has decreased so far that the gravity action on the piston 14 then overcomes this pressure. The piston 14 moves in the downward direction. During this movement air must be drawn in througl'i the bore 13 whereby the downward movement of the piston is retarded. The discharge ports remain thereby uncovered during such a period that the pressure of the air ren'iaining in the combustion space at the end c't' the compression stroke has nearly dropped to LEUHOSPlIGl'iQ pressure. When the suction action commences at the beginning of the expansion stroke of the engine piston the piston 14 has covered the discharged ports and it is sucked into its initial lowern'iost position.

The valve piston 14 illustrated in the drawing is loosely fitted in the valve cylinder and is not provided with a packing. A piston 14 provided with packing rings 16 may be used as is shown in Fig. 3, and the friction caused by the packing rings may be compensated by a spring 17 provided above the piston 14.-

Fig. 4 illustrates a further embodiment of the present invention in which the discharge ports 10 and 11 of every bra-king valve are connected to the exhaust pipe 18 of the engine by means of the interconnecting pipes 19 and 20. A shut-off valve 21 is inserted in the exhaust pipe 18 to close the latter against the atmosphere. The valve 21 remains open as long as the engine works a prime mover and also when the engine is used as a brake as long as the power absorbed during the compression stroke is suificient for obtaining the desired braking eiiect.

It now the braking effect has to be increased as may be desirable when the engine is arranged as the motor of a heavy lorry which runs down an incline the valve 21 in the exhaust pipe 18 is closed. The compressed air discharged i'rom the auxiliary devices after each compression stroke into the exhaustpipe increases then the pressure in the exhaust pipe so that the engine has to work against a super-pressure during the exhaust stroke which amounts to a considerable increase in the braking effect.

in Fig. 5 a modified form of the braking valve is shown. The casing 9 is provided with an annular chamber 22 on which sockets 23 and 24 are provided. To the socket 223 the interconnecting pipe 19 is attached and in the socket 24 a suction valve 25 is provided, influenced by a spring 26.

The piston 14 has a cylindrical bore 14 and the walls of the piston are provided with ports 27 registering with ports 28 in the valve casing when the piston is in its lowermost position. During the suctionstroke the engine draws air fromv the annular chamber 22 and the interconnecting pipes 19 through the ports 27, 28 and bore 14 of the piston 14.

The suction valve 25 prevents the formation of an underpressure.

in the upper end of the bore 14 of the piston 14 a leather disc 29 is fixed the diameter of which is slightly larger than the bore of the piston so that the disc assumes a curved position. The leather disc 29 permits air passing through the ports 27, 28 to enter into the engine cylinder but prevents the flow of air in the opposite direction, the leather disc acts as a non-return valve.

The piston is raised in the manner described above with the first constructional example at the end of the compression stroke and uncovers the discharge ports 28 so that the compressed air flows into the annular spaces 22 and into the interconnecting pipes 19 whereby the pressure in this space is raised. At the end of the following expansion stroke the piston 14 reaches its lowermost position in which the ports 28 and 27 register so that the slightly compressed air in the annular space 22 fio-ws into the engine cylinder and opposes the exhaust stroke of the piston.

It now the valve 21 in the exhaust pipe of the engine is closed the pressure in the exhaust pipe increases so that in the moment in which the outlet valves of the engine are opened the latter must overcome a certain super-pressure whereby the braking action is increased.

(Dbviously the leather disc 29 may be replaced by any other known non-return valve, for instance of the mush-room or ball type.

I claim:

1. An attachment to the cylinders of internal combustion engines for obtaining braking effects with said engines, comprising a casing fixed to the engine cylinder, a piston movable in said casing and controlling discharge openings provided in the latter, and an air cushion device cooperating with said piston, the movements of the piston being so controlled by the compression and suction action of the reciprocating engine and by the air cushion, when the easing is opened that the piston uncovers the discharge ports and permit the escape of the compressed air from the engine cylinder, whereby the latter acts as a compressor.

2. An attachment to the cylinders of internal combustion engines for obtaining braking effects with said engines, comprising a casing fixed tothe engine cylinder and having a cylindrical bore, a piston movable in said bore and controlling discharge openings provided in said casing, and a cover closing the latter and provide-d with a comparatively small bore so that the space between the piston and the cover acts as an air-cushion to said piston, the movements oi? the piston being so controlled by the compression and suction action of the reciprocating engine and by the air cushion when the casing is opened that the piston uncovers the discharge openings and permit the escape of the compressed air from the engine cylinder, whereby the latter acts as a compressor.

3. An attachment to the cylinders of internal combustion engines for obtaining braking effects with said engines, comprising a cut-off organ screwed to the head of each engine cylinder, a valve casing screwed to said cutoff organ and having a cylindrical bore, a piston movable in said bore and adapted to control discharge openings provided in said valve casing and a cover closing said valve casing and provided with a comparatively small bore so that the space between the piston and the cover acts as an air-cushion to said piston, the movements of the piston being so controlled by the compression and suction action of the reciproeating engine and by the air cushion when the shut-off organ is opened that the piston uncovers the discharge openin s and permit the escape of the compressed air from the engine cylinder, whereby the latter acts as a compressor.

4:. An attachment to the cylinders of internal combustion engines for obtaining braking efiects with said engines, comprising a cutof? organ screwec to the head of each engine cylinder, a valve casing screwed to said cut-oil organ and having a cylindrical bore, a hollow piston movable in said bore and adapted to control discharge openings provided in said valve casing and pro vided with ports registering with said discharge openings when the piston is in its lowermost position, a non-return valve arranged inside the hollow piston and co-operating with the ports in the p on, and a cover closing said valve casing and provided with a comparatively small bore so that the space between the piston and the cover acts as an aircushion to said piston, the movements of the piston being so controlled by the compression and suction action of the reciprocating engine and by the air cushion when the shut-off organ is opened that the piston uncovers the discharge openings and permit the escape of the compressed air from the engine cylinder, whereby the latter acts as a compressor.

5. An attachment to the cylinders of internal combustion engines for obtaining braking effects with said engines, comprising a cut-off organ screwed to the head of each engine cylinder, a valve casing screwed to said cut-0E organ and having a cylindrical bore, a hollow piston movable in said bore and adapted to control discharge openings provided in said valve casing and provided with ports registering with said discharge openings when the piston is in its lowermost position, a non-return valve arranged inside the hollow piston and co-operating with the ports in the piston, a suction valve in connection with said discharge openings, and a cover closing said valve oasing and provided with a comparatively small bore so that the space between the piston and the cover acts as an air-cushion to said piston, the movements of the piston being so controlled by the compression and suction action of the reciprocating engine and by the air cushion when the shutoff organ is opened that the piston uncovers the discharge openings and permit the escape of the compressed air from the engine cylinder, whereby the latter acts as a compressor.

6. In an internal combustion engine means for adapting said engine to act as a brake and comprising a shut-off organ fixed to the engine cylinder, a valve casing connected to said cut-off organ, a piston movable in said casing and controlling discharge openings provided in the latter, and an air cushion device cooperating with said piston, the movements of the piston being so controlled by the compression and suction action of the reciprocating engine and by the air cushion when the shut-off organ is opened that the piston uncovers the discharge openings and permits the escape of the compressed air from the engine cylinder, \VllQ-I'QlE the latter acts as a compressor, a connection be tween said discharge openings and the exhaust pipe of the engine, and a shutoff organ to close the exhaust pipe against the atrnosphere.

7. In an internal combustion engine means for adapting said engine to act as a brake and comprising a cut-off organ screwed to the head of each engine cylinder, a valve casing screwed to said cut-oft organ and having a cylindrical bore a piston movable in said bore and adapted to control dis charge openings provided in said valve casing, and a cover closing said valve casing and provided with. a comparatively small bore so that the space between the piston and the cover acts as an air-cushion to said piston, the movements of the piston being so controlled by the compression and suction action of the reciprocating engine and by the air cushion when the shut-oi? organ is opened that the piston uncovers the discharge openings the compressed air from the engine cylinder, whereby the latter acts as a compressor, a connection between said discharge openings and the exhaust pipe of the enginaand a shntcii' organ to close theexhaust pipe against the atmosphere.

In testimony whereof I afiix my signature.

RICHARD KR-UTINA.

and permit the escape of 

